Barb, I used 3/4 thick poplar. I used my table saw to rabbit the inside edges of the poplar, I placed the blade at the depth I wanted, in this case 1/2 inch, and set the fence for the amount I wanted to be in from the edge. Then I cut the waste by resetting the blade and passing the pieces through on their edge. I used my router to round over the outer edges, then did my miters. Hope that makes sense After glue up I place splines in the corners for strength and decoration. There are several easy to make spline jig plans online. I place the 1/8 inch backer inside the rabbit and use a Logan picture frame point stapler to place the hold downs on.